Date:         Thu, 2 Jan 1997 14:13:06 -0500 (EST)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Cetin  Seren <cseren@fore.com>
Subject:      how engine oil degrades (was: sysnthetic oils)

Happy new yaer everyone....

(I've been meaning to send a notice to teh list on this for a few
weeks now)...

In Early december I 'stumbled' on one more possible reason why engine
oil may break down, thought I should warn the list members:

On one exceptionally warm day in December, my '87 vanagon's oil light
and buzzer came on while driving.  I immediately stopped, waited about
3-4 minutes for the oil (or most of it) to settle in the crancase,
checked oil level, it was nearly full.   Scared, I began driving
again, no oil light or buzzer for a few minutes, then it came on
again.  Like everyone else who ran into this event, i I revved the
engine, the buzzer and the light would go off.  I limped the '87 to my
place, and checked the oil level once again, almost full -- BTW, what
was that smell??? Then I slapped myself on the head: the oil smelled
of gasoline!!!! Somehow, it mixed in (the fact that the van idles high
until it warms up? the few times I cranked it too long and flooded it?
the fact that the engine now has 142,000 miles on it? some other
defect  somewhere else that I cannot think of?).  In any case, the
buzzer and the light were coming on because the oil was thinned down
by the gasoline that somehow mixed in.
Anyways, the 'cure' was an oil change with 20W50 oil...  I've been
'sniffing' the oil reasonably frequently now, and no smell of gasoline
yet. 

I guess things that are not exactly mentioned in the service manuals
do come up as an engines get old.....

Thought I'd share it with the list....

Cetin


Will Wood writes:
 > 
 > The synthetics give you extended life since all crude based oils start
 > breaking down after
 > a while.
 > 
 > But it's the dirt that causes the most damage, that's why even using a
 > synthetic you need
 > to change it frequently.  Mobil One used to advertise that you could go
 > 25,000 miles between
 > changes, imagine that in a Diesel motor. (Those of you with Diesels will
 > bear me out).
 > 
 > Synthetics also don't break down at high temperatures, but I'll submit that
 > if your upright
 > is running that hot, it'll be melted down anyway.
 > 
 > 
 >